Add socket.io for real time raffle updates.

Change-Id: Iaacb3e899727a6b6803aadcfd6ff0008ecdd2137
Added qr code to winner status page.

Change-Id: If9830672c9c09a007ec0c947199bd566ee066932
Close sockets when controller is destroyed.

Change-Id: I0cd1cc831b48f9a04948db9c284d4b8545adf036